Screeding apparatus and method

An improved self-propelled screeding apparatus for loose or plastic materials such as placed and/or poured, uncured concrete previously placed on the ground or another support surface, said apparatus being of the type including a frame, propulsion means on said frame for moving said frame over the ground or a support surface, a boom, boom support means for mounting said boom on said frame, a screed assembly, and screed mounting means for mounting said screed assembly on said boom, the improvement comprising:

• said screed assembly being elongated and including a striker for engaging and spreading the material, means for moving the material along the direction of elongation of said screed assembly, and vibration means for engaging, vibrating and smoothing the material;
• articulated means for pivotally mounting said screed assembly on said screed mounting means on a first pivot axis extending generally parallel to the direction of elongation of said screed assembly;
• motive power means on said screed assembly for pivoting said screed assembly including said striker, said means for moving the material along the direction of elongation of said screed assembly, and said vibration means in unison about said first pivot axis;
• and
• said boom being a telescoping boom assembly including a plurality of telescoping sections and boom extension means for extending and retracting a free end of said boom by moving said sections with respect to one another, said screed assembly and screed mounting means being mounted at said free end of said boom whereby said articulated means and motive power means allow said screed assembly to be pivoted about said first pivot axis as said boom sections are moved along the material to maintain proper screeding while counteracting the force of concrete resisting movement of the screed assembly.

An improved self-propelled screeding apparatus for loose or plastic materials such as placed and/or poured, uncured concrete previously placed on the ground or another support surface, said apparatus being of the type including a frame, propulsion means on said frame for moving said frame over the ground or a support surface, a boom, boom support means for mounting said boom on said frame, a screed assembly, and screed mounting means for mounting said screed assembly on said boom, the improvement comprising:

• said screed assembly being elongated;
• articulated means for pivotally mounting said screed assembly on said screed mounting means on a first pivot axis extending generally parallel to the direction of elongation of said screed assembly;
• motive power means on said screed assembly for pivoting said screed assembly about said first pivot axis;
• and
• said boom being a telescoping boom assembly including a plurality of telescoping sections and boom extension means for extending and retracting a free end of said boom by moving said sections with respect to one another, said screed assembly and screed mounting means being mounted at said free end of said boom whereby said articulated means and motive power means allow said screed assembly to be pivoted about said first pivot axis as said boom sections are moved along the material to maintain proper screeding while counteracting the force of concrete resisting movement of the screed assembly;
• said boom extension means including boom power means for extending and retracting said boom sections and said screed assembly;
• said boom power means including a fluid cylinder mounted on one of said boom sections and engaging said frame for extending and retracting said one section with respect to said frame, and pulley and cable means on said one boom section and a second boom section for extending and retracting said second boom section with respect to said one boom section and said frame as said one boom section is moved with said fluid cylinder.

A method of screeding material such as placed and/or poured, uncured concrete with a screed assembly comprising:

• moving the screed assembly through the material in a predetermined direction to spread, grade and smooth the material including supporting said screed assembly on an extendable, telescoping boom assembly, positioning said boom at approximately a 2% slope with the free end of said boom lowermost, and retracting said boom assembly with said screed assembly thereon along the upward incline provided by said 2% slope at a predetermined rate;
• pivoting the screed assembly about an axis perpendicular to said predetermined direction during such movement to counteract the force of the material acting on said screed assembly and to maintain effective screeding contact of said screed assembly with the material during such movement;
• moving the material with said screed assembly in a lateral direction across the path of travel to form an evenly distributed layer of the material while said boom assembly and screed assembly are being retracted;
• vibrating a portion of said screed assembly to smooth the distributed layer of material while isolating the vibration from the remainder of said screed assembly;
• and
• controlling the elevation of said screed assembly with respect to a fixed reference located external to said screed assembly with a control assembly on said screed assembly.

A vibratory screed for a screeding apparatus comprising:

• an elongated, generally horizontally extending screed support;
• a pair of vertically spaced, elongated beams, each beam being in one piece and extending generally horizontally across said screed support;
• resilient mounting means for mounting and vibrationally isolating said beams on said screed support;
• an elongated screed strip on the lowermost of said elongated beams for engaging and smoothing material such as uncured concrete;
• brace means for vertically spacing said beams;
• and
• rotatable shaft means having eccentric weights thereon for vibrating said elongated screed strip when rotated.